The Pawpaw (Asimina triloba) is a small deciduous fruit tree most commonly found near creek banks and river bottoms in the understory of rich broadleaf forests of the eastern United States. It has the largest edible fruit native to North America, with a flavor somewhat similar to banana and mango. It is notable for having more protein than most other fruits.
"The fossil record indicates that the pawpaw's forebears established themselves in North America millions of years before the arrival of humans. The Native Americans were great lovers of the pawpaw and introduced it to European explorers: the DeSoto expedition of 1540 reported encountering tribes that cultivated the fruit. In 1736, Quaker botanists John Bartram and Peter Collinson arranged for specimens to be sent to England." -- The Pawpaw Foundation
The Pawpaw tree fits in as excellent understory tree in a large forest garden, or even as the main fruit tree in smaller forest gardens. The fruit is both tasty and highly nutritious, containing a surprising amount of protein.
Another advantage of the Pawpaw is that it has few pests and requires little or no pesticides in its cultivation. In fact, its leaves, twigs, and bark contain natural insecticides known as acetogenins, which can be used to make an organic pesticide.
Pawpaw seeds also have these insecticidal properties. Native Americans dried and powdered them and applied the powder to children's heads to control lice, and today specialized shampoos for eliminating lice are made using compounds from pawpaw seeds.
Pawpaw flowers are pollinated by carrion beetles and blowflies, but have a weak scent which can limit production. Some growers place rotting meat near the trees to increase the blowfly population to help with pollination.
The Pawpaw tree is the only larval host of the Zebra Swallowtail Butterfly, so by planting Pawpaws you are helping the survival of the Zebra Swallowtail.
According to The Pawpaw Foundation, "since 1900, numerous individuals, including the renowned botanist David Fairchild, have collected superior clones from the wild and worked at improving the pawpaw. Roughly a dozen named varieties exist; most notable are Sunflower, Overleese, and Taytwo."
(This article is from an old blog of mine, originally written in 2010.)